The importance of
estrogen in vascular
neoplasia is suggested by a predilection for women and a tendency for rapid growth during pregnancy. Although early experiments using radioligand assays demonstrated
estrogen receptor (ER) expression, these findings were not confirmed by subsequent immunohistochemical studies which were performed with
antibodies raised against ER alpha. A newly discovered
estrogen receptor subtype, ER beta, has not been previously characterized in vascular lesions. In order to verify the expression of
estrogen receptors in
vascular neoplasms as well as to clarify the inconsistency between radioligand and early immunohistochemical studies, we examined a series of 53 benign and malignant
vascular neoplasms for ER beta expression. All of the subtypes of vascular
neoplasia examined had nuclear expression of ER beta. The majority of cases (94%) displayed 2+ to 3+ staining. The discrepancy between radioligand studies and previous immunohistochemical studies is attributable to the use of
antibodies raised against ER alpha, which is not expressed in vascular lesions, and not ER beta, which is broadly expressed in both benign and malignant
vascular neoplasms. Although ER beta may be of limited diagnostic use in vascular
neoplasia due to its broad expression, the potential exists for a therapeutic approach using ER agonists.